1. Field of the Invention
The present invention relates to a dye mordant composition containing a certain polymer compound useful in a silver halide photographic element.
2. Description of the Prior Art
It is well known in the photographic art that various kinds of polymer materials and mordants can be employed with the intention of preventing dyes from diffusing in a color image transfer element which comprises a support and a silver halide emulsion-containing layer. Image receiving elements containing mordants are described in, for example, U.S. Pat. Nos. 2,584,080 and 3,770,439. Certain, water-insoluble mordant polymers have already been produced as disclosed in U.S. Pat. No. 3,898,088. Mordants of this kind not only have excellent dye retention properties but also have extremely low diffusibility.
The use of these polymers as a mordant is accompanied by the disadvantage that they must be dissolved in a 40% by weight alcohol solution (and generally, in a methanol-water solution). The use of a large quantity of such alcohol solutions causes difficulties in that not only must extra expense be borne in order to eliminate the alcohols contained therein, but also another, different kind of coating process e.g., a coating process using a solution thereof in an organic solvent such as methanol, ethanol, etc. is required. In addition, it is difficult to form a homogeneous and uniform coating using conventional coating compositions because of the high viscosity of the coating composition containing such.
Further, the application of mordant polymers of this kind to an image receiving layer in the diffusion transfer process gives rise to a serious problem called the "after-transfer" phenomena, which term is used herein to describe the increase with the passage of time in the density of the transferred dye image beyond that necessary with the balance between the color densities of the image being destroyed.
On the other hand, mordant polymers which are disclosed in Japanese Patent Application (OPI) No. 71332/75 (corresponding to U.S. Patent Application Ser. No. 517,561, filed Oct. 24, 1974) do not give rise to the after-transfer phenomena, but a demordanting phenomena in a low pH range, e.g., about 2 to about 8, occurs to result in a reduction in the quality of the image due to the fading of the transferred dye image. Furthermore, when the mordant polymers used are hydrophilic, they have an additional disadvantage in that they diffuse into other layers because of their water soluble property in photographic layers.
As used herein, the term "demordanting phenomena" means the gradual decrease in the density of the transferred dye image with the passage of time.
Many investigations have been undertaken with the intention of discovering mordant polymers which are capable of strongly mordanting dyes, which are essentially non-diffusible and with which the after-transfer phenomena does not occur.